I've got this HeNe power supply that runs off the mains. But the problem is it takes 115 Vac (designed for the US mains where you have 120 volts). Here in the southern hemisphere electricity is distributed as 50 Hz ac at ~230 V.

I think the psu has some kind of rectifier to get dc, and then perhaps a boost converter after that. But I wouldn't know what are their tolerance/compliance. So what is likely to happen if I connect this to a tube and switch it on?

Is it very risky to try the psu on the tubes?? (I don't want to ruin the tubes, or the psu)

Can you not use one leg of the 220VAC? One lead (going to ground) should be 120v volts, more or less. And the 50Hz versus the 60Hz should not be an issue.

If you're afraid of screwing something up, it will likely be the power supply and not the tube. If you are squeemish, power just the PSU without the HeNe connected for a few minutes. If it doesn't heat up or explode, you can feel confident it will not hurt the tube.

Pschlosser, not sure if that works, I think it's 230 V with respect to ground/zero voltage reference node.

I think I'll opt for the transformer option. I don't want to run the risk of damaging the ps.
Things, the Jaycar transformer's input doesn't have the same socket type as the ps. The cheap transformers on ebay have the same problem. What kind of adapter do I need?

It could be possible that the loop of wire is the voltage doubler link. Some switching power supplies (PC supplies too) have a link that you short for 120V operation and leave open for 240V operation. We can't know for sure on your PSU unless we have the manual

It could be possible that the loop of wire is the voltage doubler link. Some switching power supplies (PC supplies too) have a link that you short for 120V operation and leave open for 240V operation. We can't know for sure on your PSU unless we have the manual

Nope. I forget what it's called but it cut the power to the PSU. I am sure someone will chime in it's use.